Hib Vaccination Schedule for Children

Standard Primary Vaccination Schedule

The Centers for Disease Control and Prevention recommends that children should begin receiving the Haemophilus influenzae type b (Hib) vaccine at 2 months of age, with the vaccination series able to start as early as 6 weeks of age 1, 2, 3
For PRP-T Vaccines, the primary series consists of 3 doses given at 2, 4, and 6 months of age, and a booster dose at 12-15 months of age 1, 2
The minimum age for the first dose is 6 weeks, and doses should be spaced at least 2 months apart 1, 2
For PRP-OMP Vaccines, the primary series consists of 2 doses given at 2 and 4 months of age, and a booster dose at 12-15 months of age 1, 3
For Combination Vaccine (DTaP-IPV-Hib-HepB/Vaxelis), the primary series consists of 3 doses at 2, 4, and 6 months of age only, with a minimum age for the third dose of 24 weeks 4

For children 7-11 months who are previously unvaccinated, the Centers for Disease Control and Prevention recommends 2 doses of HbOC vaccine given at least 2 months apart, plus a booster at 15 months, or 2 doses of PRP-OMP vaccine given 2 months apart, plus a booster at 15 months 1, 2, 3
For children 12-14 months who are previously unvaccinated, a single dose should be given before 15 months of age, followed by a booster at 15 months 1, 2
For children 15-59 months who are previously unvaccinated, a single dose only is needed, with no additional doses required for healthy children, unless high-risk conditions exist 1, 2, 5

High-risk children aged 12-59 months, including those with functional or anatomic asplenia, HIV infection, immunoglobulin deficiency, early component complement deficiency, or receiving chemotherapy or radiation therapy, require additional doses 5
Children ≥60 months (5 years and older) generally do not require Hib vaccination unless they have high-risk conditions, in which case a single dose of any licensed Hib conjugate vaccine is recommended 5

After natural Hib disease, children <24 months who develop invasive Hib disease should still receive vaccination, as natural infection at this age does not reliably produce protective immunity 1, 6
Ideally, the same conjugate vaccine should be used throughout the entire series, but if the previous vaccine type is unknown, ensure infants aged 2-6 months receive a minimum of 3 doses total of any conjugate vaccine 1, 2
Hib vaccines can be given simultaneously with DTP, MMR, OPV, IPV, pneumococcal, and meningococcal vaccines, and all conjugate vaccines should be administered intramuscularly 1, 2

The Advisory Committee on Immunization Practices (ACIP) recommends that Haemophilus influenzae type b (Hib) conjugate vaccines be given concurrently with pneumococcal conjugate vaccines (PCV) in infants, citing extensive pre‑licensure and post‑licensure studies that demonstrated comparable safety and immunogenicity to separate administration. Strength of evidence: high (large clinical trials and surveillance data). 7

When Hib and PCV are administered on the same day, CDC/ACIP guidelines require each vaccine to be given with a separate syringe, at different intramuscular injection sites, and never mixed in the same syringe. Strength of evidence: expert recommendation (MMWR guidance). 8

In a 2020 MMWR clinical study, the combination vaccine DTaP‑IPV‑Hib‑HepB (Vaxelis) was co‑administered with pneumococcal conjugate vaccines; the trial found no difference in safety outcomes (local or systemic adverse events) compared with separate administration. Strength of evidence: moderate (controlled trial). 9